The letters of the answer to the first part of the clue can be transposed to form the answer of the second half of the clue. If you find the first part of the clue is elusive then switch to the second part and work your way backwards

Example: transpose a garment into a tiresome person -> robe - bore

= 1. Transpose a word reference book into revelatory= 2. Transpose before existence into a guardian= 3. Transpose synthetic fabric into increasing size= 4. Transpose a follower into having a spouse= 5. Transpose hear into quiet= 6. Transpose sign up into a decoration= 7. Transpose a story into a heist= 8. Transpose not fresh into ducks= 9. Transpose a language into a shake= 10. Transpose get ready into a wall decorator= 11. Transpose an aviator into a fancy dock= 12. Transpose an advertisement into a gun= 13. Transpose an moisture remover into equestrian